What kind of mesh to use for cylindrical object in channel
 

Hi, I'm trying to simulate flow around a cylindrical 'Turbulence Enhancer' in a simple channel. I'm trying to mesh the faces and edges using Gambit's built in hexahedral meshing technique. However, I'd need to refine mesh around the cylinder wall to get better outputs. Can anyone suggest the steps needed to do that? Or do you guys think that I should use a different mesh type, like a tetrahedral mesh or something?

Oh, btw, it's a two dimensional problem. I've defined the cylinder as a circular object at the center of the channel by subtracting the circle from the channel face. Is that the right way of doing this? Or should I keep the circular cylinder edge intact and define it as a 'wall boundary' condition?

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